Herbal extract prevents bone loss in ovariectomized rats

Abstract

This research aims to test a new drug candidate based on a traditional medicinal herb, F1, an herbal extract obtained fromAstragalus membranaceus and its main ingredient, 1-monoli-nolein that may have fewer side effects and less uterine hypertrophy.In vitro experiments, human osteoblast-like cell lines, MG-63 and Saos-2, were analyzed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and an alkaline phosphatase (ALP) assays. Mouse osteoclasts were induced through a calcium-deficient diet and inhibition effects were measured.In vivo experiments were done using ovariectomized (OVX) rats for 9 weeks. At necropsy, uterus weights were measured, trabecular bone area (TBA) of tibia and lumbar vertebra were measured bone histomorphology. In results, cell proliferation and ALP activity in Saos-2 by ether F1 or 1-monolinolein did not increased significantly compared to the control. The F1 inhibited osteoclast development (IC₂₅= 3.37×10⁻⁵ mg/mL) less than 17²-estradiol. The OVX rats administered F1 (2 mg/kg/day and 10 mg/kg/day) showed an increase in TBA of the tibia significantly (136.3±4.2% and 138.5±10.3% of control). In conclusions, the herbal extract, F1 inhibited tibia and lumbar bone loss and did not cause uterine hypertrophy. However, 1-monolinolein, the main ingredient of the herbal extract, did not inhibit bone loss.